If the upcoming fall TV season were looking for a catchy slogan, it may well be, "Thanks for the memories."

Watching at home, however, you may be forgiven for asking yourself, "Haven’t I seen this somewhere before?"

With traditional, mainstream TV facing its toughest challenge in years — declining audiences, stiff competition from specialty channels and DVD sales, and a growing belief that studio-produced TV programs are not as good as they used to be — the executives who decide which TV programs you see are opting for the sure thing over the longshot.

And, in the mercurial TV business, as in the movie industry, the sure thing is most likely to be something you’ve seen before.

More than 200 pilot episodes for new series are making the rounds at the major U.S. and Canadian networks as you read this. By the middle of next month, ABC, NBC, CBS, Fox, UPN and The WB will unveil their fall schedules before advertisers in New York.

CTV, Global and CHUM will pick over those shows they consider to be the best, and announce their fall schedules in June. CBC, no longer in the buying game, will instead try to find shows of its own to replace its aging hits and recent cancellations, such as Disclosure.

You won’t notice it on your TV screen — we are about to enter the season-ending May sweeps period, when the networks roll out their season finales and big-ticket programming — but, behind the scenes there is panic as the networks try to figure out what they can do to staunch the bleeding next fall.

Despite their appetite for reruns, they don’t want a repeat of last year, when words such as "depressing," "disconcerting" and "malaise" were tossed around in the usually boastful trade papers.

Despite extensive media hype, the shows Skin, Coupling and Tarzan quickly collapsed. The few so-called hits were marginal successes at best: Las Vegas, Two and a Half Men and Joan of Arcadia.

More than 30 years ago, in the era of the three-network universe, the original Star Trek was cancelled after 2 1/2 seasons, despite pulling in 20 per cent of the audience watching TV at the time. Today, 20 per cent is what CBS pulls in on an average Thursday night, when the network airs Survivor, CSI and Without a Trace. Those are among the highest-rated programs on TV at the moment.

The rules have changed, in other words. Just last month, a research report sponsored by Turner Broadcasting projected that specialty channels would surpass the major networks in aggregate prime-time viewing during the 2003-04 season for the first time.

The networks are now inclined to throw everything they have at the wall, to see what sticks. If it doesn’t stick immediately, it’s gone. That’s why Wonderfalls vanished after just three episodes, despite what some Fox executives admit privately were some of the best reviews of any new program in the network’s 27-year history.

Reality TV, widely seen as a short-term fix to short-term ratings woes, is a two-edged sword. As many reality shows fail as succeed, and even the successful ones don’t repeat well. Viewers only want to see who wins The Apprentice once.

That’s why the networks are studying pilots for the new fall programs closely.

The next Friends will in all probability be a situation comedy, not a reality show. No one is going to buy a DVD of The Apprentice 10 years from now. Friends DVDs, however, are flying off store shelves like there’s no tomorrow. And old episodes of Friends are liable to be shown on syndicated and local stations for years, if not decades, to come. That’s why, beginning this fall, a lot of the new shows you see will resemble Friends, in tone if not in fact.

There are bright, original ideas out there, but many never make it to air. The problem is, given a choice, network executives with an eye for the bottom line will opt for the safe route every time. And nothing is safer than going with what has been proven to be a success before. That means more family-driven sitcoms in the vein of According to Jim. More forensic crime dramas in the vein of Cold Case and Crossing Jordan. And more reality TV.

Imitation is the sincerest form of television, the legendary comedian Fred Allen said, shortly before his death in 1956. That’s why, beginning this fall, you’ll see CSI: New York and Law & Order: Trial by Jury.